Ventilatory Efficacy After Transcatheter Aortic Valve Replacement Predicts Mortality and Heart Failure Events in Elderly Patients

Abstract

Background:We aimed to clarify the predictors of death or heart failure (HF) in elderly patients who undergo transcatheter aortic valve replacement (TAVR). Methods and Results:We prospectively enrolled 83 patients (age, 83±5 years) who underwent transthoracic echocardiography (TTE) and cardiopulmonary exercise testing (CPET) with impedance cardiography post-TAVR. We investigated the association of TTE and CPET parameters with death and the combined outcome of death and HF hospitalization. Over a follow-up of 19±9 months, peak oxygen uptake (V O2) was not associated with death or the combined outcome. The minimum ratio of minute ventilation (V E) to carbon dioxide production (V CO2) and the V E vs. V CO2 slope were higher in patients with the combined outcome. After adjusting for age, sex, Society of Thoracic Surgeons score and peak V O2, ventilatory efficacy parameters remained independent predictors of the combined outcome (minimum V E/V O2: hazard ratio, 1.108; 95% confidence interval, 1.010-1.215; P=0.031; V E vs. V CO2 slope: hazard ratio, 1.035; 95% confidence interval, 1.001-1.071; P=0.044), and had a greater area under the receiver-operating characteristic curve. The V E vs. V CO2 slope ≥34.6 was associated with higher rates of the combined outcome, as well as lower cardiac output at peak work rate during CPET. Conclusions:In elderly patients, lower ventilatory efficacy post-TAVR is a predictor of death and HF hospitalization, reflecting lower cardiac output at peak exercise.